Surgical procedures often rely on precise positioning to locate particular surgical targets without disturbing nearby structures that may adversely affect the surgical results. Open field surgery relies on a steady hand and sharp eye of a surgeon for ensuring that surgical intervention is focused accordingly. In recent decades, endoscopic and laparoscopic techniques perform minimally invasive procedures with elongated instruments by working through small incisions, rather than a large open field. Many procedures involve simply locating and removing a harmful growth or structure, such as a tumor, cyst or polyp. In the case of kidney stones, for example, the stone may be broken up and removed, once located with endoscopic equipment.